Oral cavity, pharynx, larynx Flashcards
What are the borders of the oral cavity?
- Superior: palate(hard palate, soft palate), teeth
- Posterior: oropharynx
- Inferior: floor of mouth, tongue and teeth
- Lateral: cheeks
Describe the anatomy of the hard palate
The palate forms the superior border of the oral cavity
Hard palate = the anterior part of the palate. Has a bony structure. consists of
* Palatine process of maxilla
* Horizontal plates of palatine bones
Describe the anatomy and function of the soft palate (location, attachments, anatomy, muscles comprising)
- A moveable fold attached to the posterior edge of the hard palate that separates the nasopharynx superiorly and the oropharynx inferiorly
- Prevents regurgitation into the nasal cavity
- Extends posterio-inferiorly into a curved free margin (the uvula).
- Comprises 5 muscles:
1. Levator veli palatini
2. Tensor veli palatini
3. Palatoglossus
4. Palatopharyngeus
5. Musculus uvula
How many permanent teeth are there? What system should be used to labal dental abnormalities?
There are 32 permanent teeth.
Palmer notation chart
Which teeth are most vulnerable during airway manouvres?
What is the minimum normal interdental distance at maximal mouth opening in young adults?
The upper incisors are most vulnerable during airway manoeuvres.
37mm (95% confidence interval)
What is the mucous membrane covering the tongue comprised of?
The mucous membrane covering the tongue comprises papillae and posteriorly, lymphoid tissue, known as the lingual tonsils.
Describe the structure and function of the tongue
A muscular organ in the floor of the mouth. Together with the teeth and the floor of the mouth, forms the inferior border of the oral cavity.
Function:
* Squeeze food into the pharynx
* Assist in word formation
Structure:
* Covered by a mucous membrane comprising papillae and lymphoid tissue
* Extrinsic muscles (originate outside the tongue and insert into it. Responsible for tongue movement.)
* Intrinsic muscles (responsible for alterations of tongue shape)
Describe the extrinsic muscles of the tongue
The extrinsic muscles originate outside the tongue and insert into it. They are responsible for tongue movement.
1. Genioglossus
2. Hyoglossus
3. Styloglossus
4. Palatoglossus
Describe the intrinsic muscles of the tongue
The intrinsic muscles of the tongue are responsible for alterations of shape
* Inferior longitudinal muscle
* Superior longitudinal muscle
* Transverse muscle
* Vertical muscle
Describe the innervation of the tongue
Motor function:
* hypoglossal nerve (CN XII)
* except palatoglossus, which is supplied by a branch of the vagus nerve (CN X)
Sensation:
* Anterior 2/3: general sensation supplied by lingual nerve, a branch of CN V3 (mandibular branch of trigeminal). Taste supplied by chorda tympani from facial nerve (CN VII)
* Posterior 1/3: lingual branch of glossopharyngeal (CN IX) supplies general sensation and taste
Parasympathetic secretory function: chorda tympani from facial nerve (CN VII)
Describe the anatomy and function of the floor of the mouth
Which muscles make up the floor of the mouth
Forms part of the inferior border of the oral cavity. Provides a muscular bed on which the tongue rests, and a framework for two glands:
* sublingual
* submandibulary salivary
Muscular bed consists of:
* Digastric and stylohyoid: arising at skull base and inserting into the floor of the mouth
* Mylohyoid: spans the mandible, forms a sling across the floor of the mouth
Name 3 factors that contribute to mouth opening
What is the minimum normal interdental distance at maximal mouth opening in young adults?
Temperomandibular joint
Mandibular length
Cranio-cervical mobility
37mm (95% confidence interval)
Describe the pharynx
The pharynx is a funnel-shaped fibromuscular tube that is the common passage for air into the trachea and food into the oesophagus
The interior of the pharynx can be divided into
* Nasopharynx
* Oropharynx
* Laryngopharynx
Describe the muscular structure of the pharynx
The pharyngeal skeleton is made up of a fibromuscular tube with external circular muscles and inner longitudinal muscles.
External circular muscles (made up of the constrictor muscles)
* Responsible for propelling food into the oesophagus
* Superior constrictors
* Middle constrictors
* Inferior constrictors
Inner longitudinal muscles
* Responsible for elevating the larynx and pharynx during swallowing and speaking
* Stylopharyngeus
* Palatopharyngeus
* Salpingopharyngeus
Name the external circular muscles of the pharynx
- Superior constrictor
- Middle constrictor
- Inferior constrictor